Nami Kumagai is a female high school student with waist-length brown hair and green eyes. She attends the same school as the protagonist, Yuu Asakura, who finds her attractive yet initially interacts little with her. She is the daughter of Kengo Kumagai, whose criminal activities unintentionally place her in danger, entangling her in violent conflicts stemming from his illicit dealings. Her development occurs when she witnesses Yuu Asakura's violent transformation under the influence of a cursed revolver amplifying dark impulses; this exposure is a direct consequence of her father's criminal associations, forcing her into the path of the gun's destructive influence. She becomes a victim of circumstances beyond her control, particularly when her father is targeted by Yuu under the gun's malevolent sway. Her role includes being present during confrontations tied to her father's fate, including an instance where she is abducted alongside him. Within the OVA's episodic structure, Nami's presence is largely reactive. She experiences the consequences of the cursed gun's propagation of violence but does not undergo resurrection or reappear in subsequent episodes after critical events. Her storyline concludes without detailed exploration of her ultimate fate following the abduction, leaving her narrative arc focused on her victimization and the traumatic impact of the gun's influence.